Can AMS reveal deformation history of serpentinized orogenite peridotite?
| Autor: | Kusbach, V., Schulmann, K., Ulrich, S., Machek, M., Roxerová, Z. |
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| Rok vydání: | 2023 |
| Zdroj: | XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
| DOI: | 10.57757/iugg23-0296 |
| Popis: | The orogenic peridotite body Mohelno represents an ultramafic igneous rock of asthenospheric origin located in the Moldanubian Zone (the eastern margin of the Bohemian Massif, Czech Republic), which is interpreted as a deep part of the thickened orogenic root developed during Variscan continental convergence. The Mohelno body represents a large scale fold structure that underwent a complex tectonic and metamorphic history. It records deformation in mantle, emplacement into lower orogenic crust and exhumation within granulite complex to middle crustal levels. The oldest part of the evolution is partially recorded by the crystallographic preferred orientation of olivine and orthopyroxene preserved in coarse-grained relics of the Mohelno peridotite. This original structure is reworked by pervasive deformation resulting in ultramylonitic fabric. Later in the middle crustal conditions, the peridotite is affected by the serpentinization to various degree, thus original anisotropy of magnetic susceptibility (AMS) record is disturbed and difficult to interpret. Modeling of AMS using the topotactic relationships between olivine and orthopyroxene and newly growing serpentine minerals + magnetite helped us to understand the AMS evolution during the serpentinization process. This enables us to relate distinct AMS fabrics to original mantle structure of olivine and pyroxenes and to late deformation evolution of already serpentinized peridotite. The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) |
| Databáze: | OpenAIRE |
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